The westernmost languages of the Austronesian family show verbal alternations that are traditionally referred to as a voice system. This paper investigates the syntax of the voice system in Mandar, a language of the South Sulawesi subfamily. It argues that this alternation tracks alternations in argument structure, determines patterns of Case-Licensing in the voicep, and positions a single argument, the pivot, to raise to the highest a-position in the clause. The process that positions the pivot is decomposed into two steps: first, a process of Object Shift that moves definite arguments out of the vp and second, a process that places the pivot in spec,tp as the result of Case-Licensing by t0. Evidence for this analysis is drawn from contexts where the external argument undergoes $${\bar{\textsc {a}}}$$
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-extraction and the internal argument is definite. In that context, the language employs a special construction which allows the external argument to be the pivot, allows the internal argument to undergo Object Shift, and provides the means to Case-License it within the vp. I refer to this construction as the Agent Focus and argue that it has a syntax similar to the analogous construction in the Mayan languages of the Q’anjob’alan subfamily.